Rotary drill bits are frequently used to drill oil and gas wells, geothermal wells, and water wells. Fixed cutter drill bits or drag bits are often formed with a bit body having cutting elements or inserts disposed at select locations of exterior portions of the bit body. Drill bits and other downhole equipment may also have a variety of other abrasive and/or wear-resistant, hardfacing elements. Cutting elements and hardfacing elements can be made from polycrystalline materials.
For example, cutting elements having a polycrystalline cutting layer (or table) have been used in industrial applications including wellbore drilling and metal machining for many years. One such material is a polycrystalline diamond (PCD), which is a polycrystalline mass of diamonds (typically synthetic) that is bonded together to form an integral, tough, high-strength mass. To form a cutting element, a cutting layer is bonded to a substrate material, which is typically a sintered metal-carbide. When bonded to a substrate, a PCD is referred to as a polycrystalline diamond compact (PDC). Polycrystalline materials for use in cutting elements or hardfacing structural elements can also be made from other polycrystallline materials such as polycrystalline cubic boron nitride (PCBN).
Methods for securing thermally stable polycrystalline material to a substrate for use in drill bit cutting element, or other abrasive and/or wear-resistant, hardfacing structural element that are part of a drill bit body or other downhole equipment have been actively investigated. High temperature high pressure (HTHP) processing is a common method of attachment. However, this method typically uses another catalyst, such as cobalt, and results in reduced thermal stability of the polycrystalline material.